Answer:
value of a.b = -4
Step-by-step explanation:
We need to find a.b
a= 4i-4j
b = 4i+5j
We know that i.i =1, j.j=1, i.j =0 and j.i=0
a.b = (4i-4j).(4i+5j)
a.b = 4i(4i+5j)-4j(4i+5j)
a.b = 16i.i +20i.j-16j.i-20j.j
a.b = 16(1) +20(0)-16(0)-20(1)
a.b = 16 +0-0-20
a.b = 16-20
a.b =-4
So, value of a.b = -4
The answer is 9 Dollars per hour because 36 divided by 9 is 4 and 9 times 9 is 81.
Answer:
96 ways
Step-by-step explanation:
Given

Required
Ways to divide it into period of seconds
What this question implies is to determine the total number of factors of 86400
To start with, we determine the prime factorization of 86400
To do this, we continually divide 86400 by 2; when it can not be further divided, we divide by 3, then 7, then 11...












This implies that:

The number of factors d is the solved by:

Where

By comparison:



So:



<em>Hence, there are 96 total ways</em>
2 classes of 21 students each
21 × 2 classes = 42 students in total
42 × 3 mins = 126 minutes for 42 students
10 mins for 2 class pics = 20 minutes
126 + 20 = 146 minutes = 2 hours and 26 minutes
It should take 146 minutes (2 hours and 26 minutes) to take all the pictures.
Answer:
7/8
Step-by-step explanation:
3 1/2pies ÷ 4friends = ?
3 1/2 ÷ 4 = .875 (in decimal form)
.875 as a fraction = 7/8
each person will get 7/8 of a pie